content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package io.reactivex.common.exceptions;
  
  import static org.junit.Assert.*;
  
  import java.io.*;
  import java.util.*;
  
  import org.junit.Test;
  
  import io.reactivex.common.exceptions.CompositeException.CompositeExceptionCausalChain;
  
  public class CompositeExceptionTest {
  
      private final Throwable ex1 = new Throwable("Ex1");
      private final Throwable ex2 = new Throwable("Ex2", ex1);
      private final Throwable ex3 = new Throwable("Ex3", ex2);
  
      private CompositeException getNewCompositeExceptionWithEx123() {
          List<Throwable> throwables = new ArrayList<Throwable>();
          throwables.add(ex1);
          throwables.add(ex2);
          throwables.add(ex3);
          return new CompositeException(throwables);
      }
  
      @Test(timeout = 1000)
      public void testMultipleWithSameCause() {
          Throwable rootCause = new Throwable("RootCause");
          Throwable e1 = new Throwable("1", rootCause);
          Throwable e2 = new Throwable("2", rootCause);
          Throwable e3 = new Throwable("3", rootCause);
          CompositeException ce = new CompositeException(e1, e2, e3);
  
          System.err.println("----------------------------- print composite stacktrace");
          ce.printStackTrace();
          assertEquals(3, ce.getExceptions().size());
  
          assertNoCircularReferences(ce);
          assertNotNull(getRootCause(ce));
          System.err.println("----------------------------- print cause stacktrace");
          ce.getCause().printStackTrace();
      }
  
      @Test
      public void testEmptyErrors() {
          try {
              new CompositeException();
              fail("CompositeException should fail if errors is empty");
          } catch (IllegalArgumentException e) {
              assertEquals("errors is empty", e.getMessage());
          }
          try {
              new CompositeException(new ArrayList<Throwable>());
              fail("CompositeException should fail if errors is empty");
          } catch (IllegalArgumentException e) {
              assertEquals("errors is empty", e.getMessage());
          }
      }
  
      @Test(timeout = 1000)
      public void testCompositeExceptionFromParentThenChild() {
          CompositeException cex = new CompositeException(ex1, ex2);
  
          System.err.println("----------------------------- print composite stacktrace");
          cex.printStackTrace();
          assertEquals(2, cex.getExceptions().size());
  
          assertNoCircularReferences(cex);
          assertNotNull(getRootCause(cex));
  
          System.err.println("----------------------------- print cause stacktrace");
          cex.getCause().printStackTrace();
      }
  
      @Test(timeout = 1000)
      public void testCompositeExceptionFromChildThenParent() {
          CompositeException cex = new CompositeException(ex2, ex1);
  
          System.err.println("----------------------------- print composite stacktrace");
          cex.printStackTrace();
          assertEquals(2, cex.getExceptions().size());
  
          assertNoCircularReferences(cex);
          assertNotNull(getRootCause(cex));
  
          System.err.println("----------------------------- print cause stacktrace");
          cex.getCause().printStackTrace();
      }
  
      @Test(timeout = 1000)
      public void testCompositeExceptionFromChildAndComposite() {
          CompositeException cex = new CompositeException(ex1, getNewCompositeExceptionWithEx123());
  
          System.err.println("----------------------------- print composite stacktrace");
          cex.printStackTrace();
          assertEquals(3, cex.getExceptions().size());
  
          assertNoCircularReferences(cex);
          assertNotNull(getRootCause(cex));
  
          System.err.println("----------------------------- print cause stacktrace");
          cex.getCause().printStackTrace();
      }
  
      @Test(timeout = 1000)
      public void testCompositeExceptionFromCompositeAndChild() {
          CompositeException cex = new CompositeException(getNewCompositeExceptionWithEx123(), ex1);
  
          System.err.println("----------------------------- print composite stacktrace");
          cex.printStackTrace();
          assertEquals(3, cex.getExceptions().size());
  
          assertNoCircularReferences(cex);
          assertNotNull(getRootCause(cex));
  
          System.err.println("----------------------------- print cause stacktrace");
          cex.getCause().printStackTrace();
      }
  
      @Test(timeout = 1000)
      public void testCompositeExceptionFromTwoDuplicateComposites() {
          List<Throwable> exs = new ArrayList<Throwable>();
          exs.add(getNewCompositeExceptionWithEx123());
          exs.add(getNewCompositeExceptionWithEx123());
          CompositeException cex = new CompositeException(exs);
  
          System.err.println("----------------------------- print composite stacktrace");
          cex.printStackTrace();
          assertEquals(3, cex.getExceptions().size());
  
          assertNoCircularReferences(cex);
          assertNotNull(getRootCause(cex));
  
          System.err.println("----------------------------- print cause stacktrace");
          cex.getCause().printStackTrace();
      }
  
      /**
       * This hijacks the Throwable.printStackTrace() output and puts it in a string, where we can look for
       * "CIRCULAR REFERENCE" (a String added by Throwable.printEnclosedStackTrace)
       */
      private static void assertNoCircularReferences(Throwable ex) {
          ByteArrayOutputStream baos = new ByteArrayOutputStream();
          PrintStream printStream = new PrintStream(baos);
          ex.printStackTrace(printStream);
          assertFalse(baos.toString().contains("CIRCULAR REFERENCE"));
      }
  
      private static Throwable getRootCause(Throwable ex) {
          Throwable root = ex.getCause();
          if (root == null) {
              return null;
          } else {
              while (true) {
                  if (root.getCause() == null) {
                      return root;
                  } else {
                      root = root.getCause();
                  }
              }
          }
      }
  
      @Test
      public void testNullCollection() {
          CompositeException composite = new CompositeException((List<Throwable>)null);
          composite.getCause();
          composite.printStackTrace();
      }
      @Test
      public void testNullElement() {
          CompositeException composite = new CompositeException(Collections.singletonList((Throwable) null));
          composite.getCause();
          composite.printStackTrace();
      }
  
      @Test(timeout = 1000)
      public void testCompositeExceptionWithUnsupportedInitCause() {
          Throwable t = new Throwable() {
  
              private static final long serialVersionUID = -3282577447436848385L;
  
              @Override
              public synchronized Throwable initCause(Throwable cause) {
                  throw new UnsupportedOperationException();
              }
          };
          CompositeException cex = new CompositeException(t, ex1);
  
          System.err.println("----------------------------- print composite stacktrace");
          cex.printStackTrace();
          assertEquals(2, cex.getExceptions().size());
  
          assertNoCircularReferences(cex);
          assertNotNull(getRootCause(cex));
  
          System.err.println("----------------------------- print cause stacktrace");
          cex.getCause().printStackTrace();
      }
  
      @Test(timeout = 1000)
      public void testCompositeExceptionWithNullInitCause() {
          Throwable t = new Throwable("ThrowableWithNullInitCause") {
  
              private static final long serialVersionUID = -7984762607894527888L;
  
              @Override
              public synchronized Throwable initCause(Throwable cause) {
                  return null;
              }
          };
          CompositeException cex = new CompositeException(t, ex1);
  
          System.err.println("----------------------------- print composite stacktrace");
          cex.printStackTrace();
          assertEquals(2, cex.getExceptions().size());
  
          assertNoCircularReferences(cex);
          assertNotNull(getRootCause(cex));
  
          System.err.println("----------------------------- print cause stacktrace");
          cex.getCause().printStackTrace();
      }
  
      @Test
      public void messageCollection() {
          CompositeException compositeException = new CompositeException(ex1, ex3);
          assertEquals("2 exceptions occurred. ", compositeException.getMessage());
      }
  
      @Test
      public void messageVarargs() {
          CompositeException compositeException = new CompositeException(ex1, ex2, ex3);
          assertEquals("3 exceptions occurred. ", compositeException.getMessage());
      }
  
      @Test
      public void complexCauses() {
          Throwable e1 = new Throwable("1");
          Throwable e2 = new Throwable("2");
          e1.initCause(e2);
  
          Throwable e3 = new Throwable("3");
          Throwable e4 = new Throwable("4");
          e3.initCause(e4);
  
          Throwable e5 = new Throwable("5");
          Throwable e6 = new Throwable("6");
          e5.initCause(e6);
  
          CompositeException compositeException = new CompositeException(e1, e3, e5);
          assertTrue(compositeException.getCause() instanceof CompositeExceptionCausalChain);
  
          List<Throwable> causeChain = new ArrayList<Throwable>();
          Throwable cause = compositeException.getCause().getCause();
          while (cause != null) {
              causeChain.add(cause);
              cause = cause.getCause();
          }
          // The original relations
          //
          // e1 -> e2
          // e3 -> e4
          // e5 -> e6
          //
          // will be set to
          //
          // e1 -> e2 -> e3 -> e4 -> e5 -> e6
          assertEquals(Arrays.asList(e1, e2, e3, e4, e5, e6), causeChain);
      }
  
      @Test
      public void constructorWithNull() {
          assertTrue(new CompositeException((Throwable[])null).getExceptions().get(0) instanceof NullPointerException);
  
          assertTrue(new CompositeException((Iterable<Throwable>)null).getExceptions().get(0) instanceof NullPointerException);
  
          assertTrue(new CompositeException(null, new TestException()).getExceptions().get(0) instanceof NullPointerException);
      }
  
      @Test
      public void printStackTrace() {
          StringWriter sw = new StringWriter();
          PrintWriter pw = new PrintWriter(sw);
  
          new CompositeException(new TestException()).printStackTrace(pw);
  
          assertTrue(sw.toString().contains("TestException"));
      }
  
      @Test
      public void cyclicRootCause() {
          RuntimeException te = new RuntimeException() {
  
              private static final long serialVersionUID = -8492568224555229753L;
              Throwable cause;
  
              @Override
              public Throwable initCause(Throwable c) {
                  return this;
              }
  
              @Override
              public Throwable getCause() {
                  return cause;
              }
          };
  
          assertSame(te, new CompositeException(te).getCause().getCause());
  
          assertSame(te, new CompositeException(new RuntimeException(te)).getCause().getCause().getCause());
      }
  
      @Test
      public void nullRootCause() {
          RuntimeException te = new RuntimeException() {
  
              private static final long serialVersionUID = -8492568224555229753L;
  
              @Override
              public Throwable getCause() {
                  return null;
              }
          };
  
          assertSame(te, new CompositeException(te).getCause().getCause());
  
          assertSame(te, new CompositeException(new RuntimeException(te)).getCause().getCause().getCause());
      }
  
      @Test
      public void badException() {
          Throwable e = new BadException();
          assertSame(e, new CompositeException(e).getCause().getCause());
          assertSame(e, new CompositeException(new RuntimeException(e)).getCause().getCause().getCause());
      }
  }
  
  final class BadException extends Throwable {
      private static final long serialVersionUID = 8999507293896399171L;
  
      @Override
      public synchronized Throwable getCause() {
          return this;
      }
  }
  